textproduct: Rapid City

KEY MESSAGES

-Unseasonably warm with record highs expected Saturday

-Cooler to start next week with some light precip possible Saturday night into Sunday

-Mild and dry weather then returns mid next week before another cool down toward the end of next week

UPDATE

Issued at 931 PM MDT Fri Mar 20 2026

The Red Flag Warning continues overnight for northeastern Wyoming, the Black Hills, foothills, and southwestern South Dakota given poor overnight relative humidity recovery despite light winds. Exceptionally warm for March tomorrow with highs in the mid 80s to low 90s along and south of I-90 where critical fire weather conditions are expected ahead of a cold front. This front will surge southward early evening Saturday, bringing gusty north winds and a gradual increase in relative humidity. No major changes to the forecast other than adjusting RFW to re-include the foothills, Meade County plains, and Haakon County. Spotty showers possible overnight Saturday into Sunday morning, although meager liquid amounts expected. Elevated to near-critical fire weather conditions with above average temperatures Sunday through at least next week.

DISCUSSION

(This Afternoon Through Thursday) Issued at 1113 AM MDT Fri Mar 20 2026

Mean western CONUS ridge will continue to support unseasonably warm weather through much of mid next week. A ridge topping impulse does cool things down Sunday and Monday, however things dry back out and warm up mid week as the ridge rebuilds. Warm and dry westerly flow is ongoing across the area. Thermal ridge will shift into the region with the warmest day for most areas expected to be Sat. A cool front will sag into the region Sat, with most guidance stalling this feature out INVOF of I90 until evening. Areas to the south of the front will definitely reach the low 90s, with areas along and just to the north potentially losing some mixing potential. Did adjust max temps for that. If things remain on track, record high temps will likely be set at many locations including Rapid City where the all time March highs (85 and 84 at downtown and the airport respectively) could be broken as highs are forecast to reach the upper 80s to low 90s there. Ridge topping impulse will move through Sat night with an associated cold front. A period of breezy NW winds are expected Sat evening behind the front. This system will bring a few showers to the region Sat night into Sunday, esp across NW SD. Upper ridge then rebuilds mid next week with warm and dry weather returning before another cool down occurs toward the end of the week per a strong upper trough in westerly flow, although forecast confidence late next week is low attm.

AVIATION

(For the 12Z TAFS Through 12Z Sunday Morning) Issued At 526 AM MDT Sat Mar 21 2026

VFR conditions are expected through 22/03z. After 22/03z behind a cold front, areas MVFR CIGS may develop over northeastern WY into northwestern SD along with patchy light rain (or light snow over the Black Hills).

FIRE WEATHER

Issued At 1113 AM MDT Fri Mar 20 2026

Very dry, unseasonably warm, and breezy conditions will continue through Sat. In addition, a cold front will move through Sat evening, supporting gusty north winds for a period. Given poor recovery tonight with even warmer/drier conds Sat, have extended most of the current red flag warning into Sat evening. Left the northern edge of zones out for now as a trough will settle south into the area along/north of I90 and support slackening winds. To the south, breezy winds are expected with with west winds gusting over 25 mph. Did add south central SD to the red flag warning given very dry conds with breezy WSW winds expected by afternoon. Cooler Sunday and Monday, with elevated to critical fire weather conds expected to return by mid next week.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning from 11 AM MDT /noon CDT/ this morning to 9 PM MDT /10 PM CDT/ this evening for SDZ329-331-334-335. Red Flag Warning until 9 PM MDT this evening for SDZ319>326-332- 333. WY...Red Flag Warning until 9 PM MDT this evening for WYZ314>318.